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Course Description

Credit Units: 2

Prof Olanrewaju Awotona, Email address:,Dept of Pharmacy and Pharmaceutical sciences, College of Health Sciences

Course description:

Role of plant taxonomy in traditional medicine. Scientific names and general Names of medicinal plants. Common names and vernacular names of plants. Cultivation and  Collection of plant materials. Conservation  techniques.  Cultivated plants, their wild relatives and centres of origin; inventory, botanical characteristics and cultivation of economic plants; utilization of plants; investigations of the uses of indigenous plants (ethnobotany) Deforestation, devegetation and desertification, conservation of germplasm, studies of some medicinally important families of medicinal applications e.g. Meliaceae, Myrtaceae, Solanaceae, Rutaceae, Euphorbiaceae, Zingiberaceae, Musaceae, Compositae, Pipilionaceae, Mimosaceae and Caesalpinaceae.

Course Description or Outcome 

Student should be able to recognise the scientific names, common names and relevant vernacular names of very common medicinal plants and should be able to implement principles of sustainable use of plants.

Topic 1 Botanical Nomenclature 

Botanical Nomenclature (Slide 1)

Slide 2 

Botanical nomenclature is the naming of plants and the related principles and rules.

Principles and rules of Botanical Nomenclature are developed and adapted in series of international Botanical congresses

Principles and rules are listed in International Code of Botanical Nomenclature (ICBN)

The main goal of ICBN is to provide one correct name for each taxonomic group within a stable system of names or classification. The code is reviewed every six years at international Botanical Congress(IBC). The current code , the 17th edition was published in June 2018 and arose from the conference which took place in Shenzhen in July 2017.

Slide 3

What is a scientific name

A name is merely a conventional symbol of cipher that serves as a mean of reference and avoid the need for continuous use of a cumbersome descriptive phrases

The fundamental principle of scientific nomenclature is that names must be unambiguous and universal

The formation and use of scientific names of organisms for nomenclature purposes are governed by codes of nomenclature.

Slide 4

Codes of nomenclature

There are several codes for carious forms of life on the planet .  we will be concerned with only two

International Code of Botanical nomenclature (ICBN) for plants including Fungi and Cyanobacteria

International Code of nomenclature for cultivated plants (ICNCP)

Other code exist for animals, Bacteria, and Viruses

Codes differ in what they allow in the naming of the organisms for ICBN the following are important

Tautonyms are not allowed

The starting point of nomenclature for botany is  1753  the year Linnaeus first 

Published Species Plantarum in zoology in 1758.

Slide 5 and 6

Scientific names and Common names 

Botanical names are scientific names which are universal, while common names are limited to a particular language or a group of people , or geographical location. E.g.  

Sometimes one vernacular name may be used to different taxa or one taxon may have different common names.

Capsicum spps are referred to as ‘ata’ in the Yoruba language. Meanwhile there are several species of capsicum. C. annum, C. frutesence, C. pubescens, C. chinense

Pictures of peppers and different species

Common names may be misleading e.g. egg plant – there are no eggs in the plant. Solanum melongana

Scientific names are composed of two parts, generic and specific names. 

This is called the Binomial system . it was founded by Jean Bauhin but used by linnaeus in Species Plantarum(1753)

Slide 7

Generic name

This describes the genus to which the plant belongs. It is the first name of the plant. The second name is the species name

Generic name means a collective name for a group of plants that share similar characteristics

The Specific name defines the particular plant in the generic group. Differentiates the plants in a genus.

There are … species in the genus Khaya

Slide 8 and 9

Specific names

These may refer to 

  1. distinctive morphological, ecological or chemical features e.g. Alafia multiflora, Ipomoea aquatic, Tabernaemontana elegans, Ficus religiosa
  2. Honor of an individual who first collected the species or a scientist who has contributed much to the botanical knowledge of a particular region  or axonomic group

Solanum isabellii for Isabella, Trichaulax mwasumbii Vollessen after Mwasumbi (UDSM), Sanrafaelia ruffonammari Verdc. After Christopher K. Ruffo and mmari

  • It may also refer to geographical origin e.g. Khaya senegalensis

Examples are as follows 

saharae – of the sahara 

puguensis – of Pugu

sanctae-Helena – of St Helena

aethiopicum – of Ethiopia

senegalenesis – of Senegal

ugandaense – of Uganda

it is recommended by the ICBN that the endings of names from geographical considerations end in ensis(-e), anus(-a,um), or icus (–a, -um) the specific name can not be tautonomyous. E.g. Benzoin benzoin

Generic and specific names are generally in Latin or latinised words from other languages . specific names also need to conform to certain grammatical rules depending on the form of the generic names. 

Binomials starte with the generic name which starts with a capital letter and the specific starts with a small letter. The names are always italicised or underlined when it is written in script. 

When the specific name of a plant is not known it is referred to  by the genus and spps added at the end. 

Slide 10

Naming a plant

The name of the plant is based on its original description and the earliest use of the plant being the most important. This dates back to 1753 for flowering plants when Linnaeus published the Species Plantarum.

The original description is published in a journal or any other recognised medium. Since 2012 certain PDF publications on the web are accepted. . The person who does the original description is referred to as the author of that plant and their name follows the genus and specific name in a full citation. E.g.  the names can be abbreviated according to a standard abbreviation system. The authors name is not written in italics. 

Over time things can change about the plant as the knowledge base broaden and changes. Author names can become more complicated . 

For example Grevillea pyramidalis subsp. Leucadendron ( A. Cunn.ex R.Br.) Makinson

This name reflects the view of Alan Cunningham in a book published by Robert Brown in 1830, and its status in the opinion of Bob makinson in 2000 published in the Flora of Australia Vol. 17A page 505. 


Slide 11

Rules for naming plants

Common names 

There is no universally acceptable way of writing common names. Some general recommendations are as follows

  • A name used in general sense covering a group or genus (e.g. bottlebrush, conifer, oak) start with a lower case letter, this also applies to botanical names used in a general sense e.g. acacias

If one particular species or plant is referred to then use capitals for the first letter of all words , except when there is a hyphen between two words e.g. Lemon-scented Gum

  • do not put English or vernacular names in either single or double quotation marks as these may be confused with the single quotation marks used to designate a cultivar name. Double quotation marks should never be used for cultivar names

There is no internationally acceptable way to write common names. Common names derive from the culture of the people. Very often many are not aware of the scientific names of plants. This is why it is much more important to have common names in herbal pharmacopoeias. Common names are a range of different languages. The same plant can have different common names even in the same locality. Many times across borders the name may get corrupted and be spelled in a different way, but with same pronunciation. 

Scientific names help to give identity to common names of plants. If a plant common name is know in one locality and the scientific name is also known , it is easier to identify the same plant in another country by the scientific name. 

Slide 12

Rank of Taxonomic categories

In writing Taxonomic categories of plants only the categories in bold are compulsory. 

In general references to plants the genus, species and family are sufficient . 

Category Standard suffix (ending)
kingdom -bionta
Phylum/Division – phyta
Subphylum -phytina
Class -opsida
Subclass -idae
Superorder -anae
Order -ales
Suborder -ineae
Superfamily -ariae
Family -aceae ( there are exceptions )
Subfamily -oideae
Tribe -eae
Subtribe -inae
Genus None, italicize, start with capital letter
Species None, genus name plus specific epithet, Italicise



None, genus name species and sub. name

Transfer between Ranks 

When a genus , species or subspecies is described at one rank and then transferred to another rank, the original author is placed in parentheses followed by the author who made the transfer. 

Topic 2 Cultivation and Collection of Plants

Topic 3 Bio Conservation (Plants) Cultivated plants, their wild relatives and centres of origin; inventory, botanical characteristics and cultivation of economic plants; Deforestation, devegetation and desertification

Topic 4 economic plants; utilization of plants; investigations of the uses of indigenous plants (ethnobotany)

Topic 5 studies of some medicinally important families of medicinal applications e.g. Meliaceae, Myrtaceae, Solanaceae, Rutaceae, Euphorbiaceae, Zingiberaceae, Musaceae, Compositae, Pipilionaceae, Mimosaceae and Caesalpinaceae

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